May 3, 2013 #1 N Namunah New member May 3, 2013 0 0 0 same distance against the? a boat goes 6 km an hour in still water , but takes thrice as much time is going the same distance against the current . The speed of the current ( in km /hr ) is .
same distance against the? a boat goes 6 km an hour in still water , but takes thrice as much time is going the same distance against the current . The speed of the current ( in km /hr ) is .
May 4, 2013 #3 » »[Brain]«»[Waves]«1 New member May 4, 2013 1 0 1 Let the velocity of the boat be v km/h and velocity of the current be u km/h. When the boat goes in still water, its velocity is v=6 km/h. When the boat goes against the current, its velocity is v-u=(6-u) km/h. For distance S, time taken in still water to cover the distance = S/6 seconds. For same distance S, time taken while going against the current = S/(6-u) seconds. According to given, S/(6-u) = 3*(S/6) => 1/(6-u) = 1/2 => 6-u = 2 => u=4 km/h. So, the speed of the current is 4 km/h.
Let the velocity of the boat be v km/h and velocity of the current be u km/h. When the boat goes in still water, its velocity is v=6 km/h. When the boat goes against the current, its velocity is v-u=(6-u) km/h. For distance S, time taken in still water to cover the distance = S/6 seconds. For same distance S, time taken while going against the current = S/(6-u) seconds. According to given, S/(6-u) = 3*(S/6) => 1/(6-u) = 1/2 => 6-u = 2 => u=4 km/h. So, the speed of the current is 4 km/h.
May 4, 2013 #4 » »[Brain]«»[Waves]« New member May 4, 2013 1 0 1 Let the velocity of the boat be v km/h and velocity of the current be u km/h. When the boat goes in still water, its velocity is v=6 km/h. When the boat goes against the current, its velocity is v-u=(6-u) km/h. For distance S, time taken in still water to cover the distance = S/6 seconds. For same distance S, time taken while going against the current = S/(6-u) seconds. According to given, S/(6-u) = 3*(S/6) => 1/(6-u) = 1/2 => 6-u = 2 => u=4 km/h. So, the speed of the current is 4 km/h.
Let the velocity of the boat be v km/h and velocity of the current be u km/h. When the boat goes in still water, its velocity is v=6 km/h. When the boat goes against the current, its velocity is v-u=(6-u) km/h. For distance S, time taken in still water to cover the distance = S/6 seconds. For same distance S, time taken while going against the current = S/(6-u) seconds. According to given, S/(6-u) = 3*(S/6) => 1/(6-u) = 1/2 => 6-u = 2 => u=4 km/h. So, the speed of the current is 4 km/h.